A former police superintendent has been jailed for 12 years for sexually abusing vulnerable boys in the 1980s at a Home Office attendance centre for young offenders and at a children’s home.

Gordon Anglesea, 79, is the highest-profile offender brought to justice through the National Crime Agency’s Operation Pallial, which has been investigating allegations of widespread and organised child abuse in north Wales.

Anglesea has faced claims for a quarter of a century that he preyed on young boys, and in the mid-90s was awarded £375,000 in damages after successfully suing news organisations including the Observer that had linked him to abuse.

At that time he depicted himself as an old-fashioned north Wales officer who had been inspired by the fictional neighbourhood policeman Dixon of Dock Green.

But in victims’ impact statements put before Mold crown court in north Wales on Friday, one victim said: “Anglesea was the worst. He was the man I feared most.”

A second said he had several times tried to kill himself because he couldn’t live with the memories of what “that man” had done to him.

Anglesea, a father of five, continued to protest his innocence. His barrister, Tania Griffiths QC, said the verdicts were “perverse” and unsuccessfully applied for her client to be freed on bail while he sought an appeal.

Griffiths said Anglesea and his family could lose his police pension and asked the judge to be as “humane” as possible because jail would be so difficult for him.

There were cheers from the public gallery as the judge Geraint Walters passed sentence and told Anglesea his victims had been vulnerable young people with nobody to turn to for help.

Walters said: “You do not need me to say that as a person whose obligation it was to uphold the law and protect the vulnerable, your offences against those vulnerable boys grossly abused the trust placed in you. The consequences for them has been profound, indeed life-changing.”

Anglesea was found guilty of indecent assaults on two boys aged 14 and 15. One said he had been assaulted by Anglesea in the shower and a changing room at the attendance centre he ran in Wrexham. Such centres were set up by the Home Office to provide an alternative to custody for youths, and provided physical training and woodwork lessons.

The second victim lived at a children’s home called Bryn Estyn in Wrexham. He claimed he was taken from there to various addresses and passed around “like a handbag” to men including Anglesea.

North Wales police has apologised for Anglesea’s actions and said it has changed the way it investigates such offences.

In 1994, Anglesea sued the Observer, Private Eye, the Independent on Sunday and the Welsh broadcaster HTV over allegations connecting him to abuse. During libel hearings at the high court, Anglesea, then in his late 50s and living in a seaside town in north Wales, was portrayed as a stalwart of the community, a Freemason, Rotarian, Methodist and a school governor.

The news organisations called evidence from three young men who claimed to have been Anglesea’s victims while they were teenagers at Bryn Estyn. Anglesea persuaded the jury of his innocence and he was awarded damages. The papers and broadcaster were left with a £1m legal bill.

One of the libel trial witnesses, Mark Humphries, 30, killed himself two months after giving evidence against Anglesea.

In 2012, the National Crime Agency launched Pallial at the height of the swirl of false allegations linking the Tory peer Lord McAlpine to child abuse in the Wrexham area. Its mission was to look at the allegations of sexual abuse within the care system in north Wales that once again surfaced during the scandal, which was triggered by a Newsnight report.

More than 300 people made contact with the investigation, dozens have been arrested and scores of complaints are being investigated.

It is no surprise that so many people came forward. During the Sir Ronald Waterhouse inquiry in 1997, almost 300 men and women named 148 abusers including police officers, social workers, local authority executives, senior businessmen and politicians. Waterhouse ordered that they could not be identified by the media.

Among those who have been convicted through Pallial are John Allen, a care home owner who was jailed for life, and a gang of five including a former professional wrestler, a radio presenter and a civil servant, who were found to be members of a predatory paedophile ring that abused vulnerable boys.

A number of former residents of the Bryn Estyn children’s home in Wrexham were in court to see Anglesea sentenced.